The present invention relates, in general, to a device for folding at least one sheet and, more particularly, to a sheet-folding device including driven prefolding and pressure rollers as well as a folding bar pushing the sheet into the nip of the prefolding rollers by deforming it in the folding station to take a V-shape.
In known sheet-folding devices such as shown in DE-PS 365 688, a sheet to be folded is moved into the nip of prefolding rollers by a striker, the rollers feeding the sheet when prefolded to pressure rollers for completing the folding process. If a stack of sheets consisting of a plurality of sheets is to be folded, the pressure rollers which for thickness compensation must be spring-urged against each other offer the prefolded stack of sheets considerable resistance which may damage the sheets or cause malfunctions (such as sheet-to-sheet misalignment).